StaticHandler supports tagged URI - URI with resource ETag embedded in it. The response to a tagged URI never expires and can be cached forever. This is good for resources like css, js, favicon, etc. (See the <head> section of this page.)

In the following example, /test.html references an image through its tagged URI:

An html tree can be built and modified in flexible ways. For example, we can add an element to <head> much later in the code. It's also easy to design template hierarchy, reusable routines, and custom components.